A wireless communication system has been widely developed to provide various kinds of communication services such as voice and data. Generally, the wireless communication system is a multiple access system that can support communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of the multiple access system include a code division multiple access (CDMA) system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, an orthogonal frequency division multiple access (OFDMA) system, and a single carrier frequency division multiple access (SC-FDMA) system.
The work on Public Warning Systems (PWS) within the 3GPP (3rd Generation Partnership Project) systems has focused on delivering text-based warnings of limited content to the public at a large scale. This functionality is essential in providing a basic warning system with the elements as set out in clause 4.3 of 3GPP TS 22.268 document on PWS. It is noted in PWS that content which might trigger an increase in network load should be avoided as the network likely to be under stress, and capacity diminished depending upon the nature of the emergency.